Synthesis and characterization of lanthanum chloranilate complex: Application to spectrophotometric determination of anions

Lanthanum chloranilate complex has been synthesized and characterized using different techniques like Infrared spectroscopy and CHN analysis. It has been used for the development of spectrophotometric method of determination of anions like fluoride, EDTA and iodate. The determination is based on the reaction of these anions with the lanthanum ion in the chloranilate complex resulting in the liberation of an equivalent amount of chloranilate anion, the colour of which was measured. The experimental conditions, which affect the optical density, are studied to get maximum sensitivity. Interference studies were carried out with various ions. The method has been applied to the determination of these ions in actual samples viz. EDTA in detergents and iodate in salt.